Consolidated Statements of Shareholder's Equity (Parenthetical) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Pension liability, income tax expense (benefit)	$ 512	$ (7,482)	$ (1,289)
Cash flow hedging gain (loss), income tax expense (benefit)	$ (2,404)	$ 2,472	$ (775)
Convertible Subordinated Debt [Member]
Percentage of retirement convertible notes	2.50%	2.50%	2.50%